Color photography



J. T. SVHTH` COLOR PHOTOGRAPHY.

APPLICATION FILED MAY15,1918.

VEA/TOR.

Trek/VEP.

.liti

titl

JOSEPH THOMAS SMITH, l" LONDON, ENGLAND @LR KOTOGRAPHY.

tgttadgttddo .applicaties and nay it;

To all 'whom it may concern.

ide it lrnovvn that ll, Josnrn 'llrroiuas Samar, la subject of His lt/l'ajesty King George V9 ot the United Kingdom ot Great Britain and ireland and of the British llorninions beyond the Sea and Emperor ot lndimresiding at London, Englanda have invented certain new and useful Improvements in or Relating to Color Photography, ot which the following is a specication.

The present invention relates to that branch of' photography in which a photograph in monochrome is produced on or over a color screen consisting7 of contiguous small areas ot transparent color hereinafter called the composite color screen. The monochrome photograph so obscures or covers certain of the contiguous areas of transparent color on the composite color screen that the colors passed or transmitted by the uncovered and partly covered, otherwise partly obscured, parts so unite or commingle to the visual sense as to give the effect ot a transparent picture in a certain approximation to or antichromatic with the colors of nature; and the complex or assemblage consisting" ot a positive' photograph in monochrome with the composite color screen has an ap pearance as i'f it were a true photograph .in colors. lt forms, in fact, what is called a. "heliochroine Alternatively when the photograph in monochrome is a negative formed or produced in contact with the composite color screen the ettect of the cornplea to the visual sense will be that ot a negative photograph in which the colors are .approximately complementary to those oi the object depicted: that is to say the monochrome negative in juxtaposition with its i composite color screen will appear lilre or simulate anizichromatic negativer or a showing reversed colora as red tor and blue tor yellow, colors which are proaimately complenaentaiy but prob "1 f Teictiy' so; i

pif-acess ci? photography which tinvention Y' lates hitherto been c ce -i oai-ting condi-tierna prev l indered appiieation MES Specification of Letters Patent.

Patented Sept., d? tendit, rela. serai no. aat-,rsa

quired on a lrinematograph picture Hlm; such pictures being ordinarily about one inch by threequarters of an inch.,

The limiting conditions which have rendered futile the realization of minutely Adetailed or fine textured pictures by the process of photography to which the present improvements relate are as follows.

1. `-ltlarginal or contacting defects or the color areas on the composite color screen are proportionately oit greater edect in ne 'textures than in coarse textures, so that a limit of tineness is reached at which the subversive or encroaching effect ot the marginal or contacting; detects becomes predominant, so that the color edect becomes dull and Weak.

2. Ats ruling textures especially and other textures generally, become iiner; the color intensity becomes less; owingal to the increasing thinness of line lines or line granulations, and a limit as regards neness is reached beyond which it becomes impracticable to produce and maintain sufficient intensity ot' colon.

3. impurity et color or subversive staining (Whether by surface coloring of a first color, When a second color is applied., or pene tration and didusion in the base) steps in notably in most methods and with increasing eidect 4as the texture ot the composite color screen is nner. When the base is gelatin, celluloid, or other substance capable of taking a stain which penetrates such base and the base is stained after having received a colored resist in granulations, particles or lines there must be a tendency for the color stain to sinlr in the base an diduse under the resist-particles by lateral or oblique fusion; thus injuring the. color of the resist areas.. its such injury to the color ci the resist areas must ci necessity commence the edges, this injury to the color of the resist are as Wilt be more "pronounced as the resist areas are smaller,

d., hen res l color applied method oit i gartnerls ini/"en specicationllm oi .lt'civetnber oit l ed in ci i,

th day titi the tendency of the staining color to penetrate the absorbent base and to diffuse laterally or obliquely under the resist particles but owing to imperfect contact and discontinuous texture of the impressed or printed color there is a high probability or perhaps a certainty of the stain running partly between the impressed or printed particles, and the base, and also engaging in the roughness or texture of the printed particles, both on the upper and lower side. Such printed particles never give that intimate contact with the base, that smooth exterior, and closely sealed edge which may be realized when the resist is a colored gelatin or gelatinoidsolution delivered by a ruling pen, or as a spray dot.

The object of the present invention is to obtain a new technical effect, by certain novel or improved procedures, which are hereinafter fully described, reference being had to the accompanying drawings, in which the invention is illustrated on a much enlarged scale as applied to a two colorscreen, also a screen on the two color system on which is overplaced' a system of supplementary color areas.

In the drawings Figure l represents a face View of a two color screen,

Fig. 2 a transverse section thereof,

Fig. 3 represents a ragmentary face view of a screen on the two color system on which is overplaced a system of supplementary, color areas, and,

Fig. 4 a transverse section thereof. i

Fig. 5 represents a similar view to Fig. 3 but showing a screen in which the overplaced supplementary color only takes4 or bites on one of the'colors previously pro duced. A

InFigs. 3 and 5 it is to be remarked that the overplaced color areas are depicted in their own color and not in the color which over the other colors, would be given by abv straction or obstruction.

The new technical eiiect depends on the production ofv a type ofcomposite color screen or base on which the monochrome photograph is produced, this new t pe of color screen or rbase having the fol owing characteristics.

1.* The characteristic of allowing the productionof extreme fineness of the color areas together with'purity-and brilliancy, whereby it becomes practicable to roduce pietures so line in texture as to al ow their use for such enlargement as is required in kinematograph projection.

2. Contiguity ot' the colors without subversive intermingling of lat least two colors ou the color-screen base; even when extreme iineness is realized.

3. An avoidance of or minimizing oi any subversive black or darli tint between the color areas of the screen base, even when extreme ineness 1s realized.

Y. 4. Broadly and generally the production of a composite color screen base for the monochrome photograph, which screen base is minutely detailed and at the same time clear andpure in color of the desirable inbase of mingle red, green and'blue starch grains may show accumulations or runs of thel three colors; these being more especially noticeable in portraiture as irregular reen streaks on the face.

T e means by which a color-screen base can be produced in accordance with the pres ent invention is, in general terms as follows:

(a) A surface A of cellulose ester, or salt, as nit-rate or acetate of cellulose is charged or coated with small distributed areas B of 'a water soluble colloid preparation contain-- ing a transparent color.

: (t) The' colloid areas B if not already insoluble in cold water are when necessary, or when an aqueous fluid is to be brought into contact therewith insolubilized to water and the whole is thoroughly dried.

(0)The surface A is treated for a short time with a solution of a color approximately complementar or antichrom'atic to the tint or colorof the colloid preparation the solvent being one which softens the cellulose ester but not the water soluble colloid, which now forms a resist, the exposed parts C becoming colored.,

(d) Excess color is blotted oli' or otherwise removed. Operations c and el ma be repeated to obtain a right intensity o color.

(e) The surface'A. is treated with a fiuid appropriate to remove traces of the second color which adhere mechanically to the surface of the colloid areas B; soured or acidulated water being 'generally appropriate when the'solvent 'of the second color is a iiuid base: as anilin for example.

(f) It at this stage,' either-.color requires intensication to 'realize the requisite total, general, or average approximation to neutral tint, an aqueous solution of dye may be applied to further color the colloid, or alternatively a stain appropriate to aect the cel lulose ester may be applied. ln the latter case, operation (e) may require to be repeateol.

(y) The color base., produced at stage (hwill serve, when. but tw-o colors are required, the two colors being green and red Alli neonata or near variants. A third color, blue, may now be added by cross ruling as at D, Figs. 3 and 4:, random spraying, printing or other- Wise; this third color being arrangedv or suited to take or bite on one or both ot the colors previously produced, as shown by ygli) 'llhe compositecolor screen base may now be covered with a protective Waterproof stratum E, if required, and is now ready for coating with sensitive emulsion. To more completely isolate the coloring from the emulsion the film of cellulose ester which carries the composite color screen system may be stripped from its support and ce' mented color-face downward on any con- 'lenient support, or a thickness oi cellulose resist may be built up on the screen as hereinunder described.

As notes and amplihcations on the toreoing statements in general termsthe iol owin details and particulars may be regarded as embodying characteristic iea tures ot the present-invention. Paragraph headings correspond to those of the statement in general terme.

(a) The hace or eurface of celluloee cater, and the collm'd create or linea- Although ordinary celluloid or acetate celluloid may be used, the presence ot additions, as, tor example, camphor in indeterminate quantity and quality (degree ot purilication trom the accompanying oil) may disturb operations, so, when practicable the applicant preters in the case ot the hnest screens to use a cellulose ester or a mixture ot esters Without the addition ot camphor or other solid solvent. el somewhat still 'amylacetate collodion slab forms a desirable base tor operation, and a convenient method ot retaining the hlm oi ester on the glass is to lay an edging lill ot india rubber on the margin ot the 'lace ot' the plate which is to be coated, as by painting an edging on the tace of the glass with the ollicinal liquor caoutchouc or india rubber solution oi the 1898 edition oli .Bc/tica Plzarwaacopta. @thelrwise the whole surtace ot the glass plate may be rub bored and in this case the purest bensene without any sulfur compound may be desirable. The stratum or" cellulose ester being ,y

thus obtained and conveniently supported one level and rigid support oit glass, the surface is then plotted out or partly covered as a lined or stippled system with colloid material charged with a' suitable soluble color the color being red or reddish when the second color :tor staining the ester is green or greenish as indicated in l and 2. @n the other hand the color in the colloid mixture may be green or greenish, in which case the second color iler staining the bare parts oil the ester should be red or reddish. @ther antichromatic or Alins may serve.

oured on a leveled glass approximately complementary colors ay be used, or any sequent colors as known in lthe art.

Solution of cellulose cater for #coding or coating the plate.

The quality of the pyroxylin used for this purpose is al matter ot some importance The oihcinal pyroxylin prepared according to the oiiicial instructions on page 323 of the 191e edition of the British Pharmacopia is quite satisfactory but most samples of tough or low temperature nitro-cottons of commerce, or surgical pyroay- Perfect solubility and toughness are the leading criteria.

Pyroxylin as specified 100 graine.v Arnyl acetate i duid ounces.

About l() grains ot this collodion or solution ma be used as the dose for coating a quarter-p ate-(SXdl inches); this giving a desirable thinness of iilm when the hoest lines or grains are to be formed.

oZZozal miete/Wc or ab for Zines or gramilation.

ideal. Para-rosanilin color-base l2 Weight units or grains; water 2li() Weight units or grains; glacial acetic acid l0 Weight units or grains. When vall is dissolved add heb glue la@ Weight units or grains.

Excess oit1 acetic acid should be avoided, as also the use of lishglue which is acid, as acidity ot the mixture maycause the anilin solution tor libe solution) ol green dye to adhere to the lines.

Pararosanilin color-base (as distinguished trom pararosanilin leuco-base) is regarded by chemists as triamino-phen l-carbinol, and applicant believes that this 1s the colorV -base ot the dye lrnovvn in commerce as l dia-v mond magenta. To be specially appropriate `lor use in relation to the present invention the para-rosanilin color base should be tree from phenyl or allryl substitution products which give a bluish cast to the color. .ein ordinary rosanilin base or similar base may he used but in preparing the color the crimson cast should be preferred. Crimson colors or the nature ot magenta are vvell lrnevvn to experts in anilin colors.

The heh-glue used the serntduid lrind sold commercially as lie Pages Special `ldloo'to-engraving glue for process Worlr, this is understood to be guaranteed as tree :trom acid. a

Zgreece coll/oid schittert.

.acid green color ot commerce l@ vveiglnt units or grains, viator weight unite or grazins. .ddd the tollovring mixture: Fish glue las noted abovel ld Weight units or grains; `Water 50 Weight units or grains.

Any undue acidity should be avoided as in the case of the red colloid mixture, and all such mixtures. The colloid inks for the purpose of the present invention 4may be colored to suit Whatever color combination is selectedl for the composite color screen, the selection being according to well known principles. The color must however be soluble in water.

Alternatively the colloid mixture may be uncolored and after the lines or areas are insolubilizedg they may be colored by the use of an aqueous solution of dye as eX- plained under heading (f).

The perfect adhesion o'f the colloid resist to the surface ot cellulose ester is a matter of prime importance feet the stain applied to the ester surface may diffuse bet-Ween the lines or areas of colored colloid and the cellulose ester.

To secure proper adhesion and easy flow (conditions closely interrelated) an appropriate colloid is a lirst necessity. lf the colloid layer is to be applied to the cellulose ester by ruling or the like the above-men tioned preparations of fish glue or a near technical equivalent as gum arabic are especially suitable as the fish glue preparations remain conveniently soluble during the operation oi'ruling, but in this case insolubilization ot the heh glue becomes desirable in all cases and essential when an after process of recharging with color or intensification, as described below is to be practised.

(b) lnsobubz'lc'zatz'on of the colic/ai areas or Zines and complete rg/z'ngf-To insolubilize the fish glue ruling, the ruled plate is by preference exposed to the vapor of formaldehyde, conveniently Afrom an aqueous solution of -formaldehyde; another method being to. add a soluble chromate to the ruling ink or mixture, and to allow time or light, or

both to bring about insolubility of the dry lines. l

Insolubilization of sh lue areas in a vapor bath of Atormalde yde has been touched upon, but il desired the formaldehyde vapor bath may be used for a supplementary hardening, alternatively a formaldehyde liquid bath may be used for any colloid areas or lines which are not immediately soluble in cold water. For the first stage in insolubilizing the areas of unchromated fish glue, the formaldehyde vapor is ot .great value, as it in no sense or degree impairs the .sharpness or perfection of the mar inal parts of the areas.

A. ter insolubilization, and before the next stage, (c), the gelatinous or gelatinoid areas or lines should be thoroughly desiccated: this being conveniently done by slight warmth, or by leaving the surface tor a 'time in a cold drying box containing 'for example calcium chlorid..

(c) Staining the cellulose ester be'zifween the as if adhesion is imper gelatz'nous m' gelatz'noia meca-The solvent of the staining fluidy should be of such a nature as to penetrate, soften, or incipiently dissolve the bare surface of the cellulose ester, but not so active as to in any way at feet, attack or soften the colloid areas, in the sense of making the base so pasty or soft as to bring about removal of the lines or areas of resist material, videlicit colloid.

Ordinary alcohol, methyl alcohol, and acetone as such, and while anhydrous fulfill the above conditions but as in drying or evaporating these solvents adsorb moisture, their use often or generally involves a slight sub* versive staining of the colloid arcas, the aqueous residue drifting over, to the colloid resist and staining it.

A solution of anilin color in anilin itself is well known as an ink for writing on celluloid and is especially suitable, as ofthe colloid areas is not stained or attacked, provided that the herein stated precautions are observed.

Solutions .suitable tor the purpose of the present invention are as follows l. Anilin of the grade sold commercially as analytical reagent or A. 10() weicht units or grains. Acid green anilin color, l2 weight units or grains.

2. Anilin as above 100 weight units or grains. Methyl red anilin color Ll weight units or grains.

The plate bearing the stratum of cellulose ester on which are greenish or reddish lines ot colloid, as described, having been well desiccated is quickly and uniformly brushed or inopped or soit rollered over with the green or the red dye dissolved in anilin, the green solution being used it the colloid lilies are red, and the red solution being used it the colloid lines are green.

(d) Blotting Ufff-Alter a short interval, 3 to 30 seconds for example, the excess is blotted off with a soft pad, and if necessary other similar applications and blottings oil follow. By several short treatments, ascontrasted with one prolonged action the tendency of the dye to penetrate laterally or obliquely under the colloidlines is diminished or minimized. The adjustment of the activeness of the solvent in relation to the quality of the base of ester., celluloid or the like, is an important aspect of the present invention. As above stated the purer anilin sold as analytical reagent is the preferred solvent and it is believed that this will generally and perhaps invariably suit a surface of lilm consisting oi the pure cellulose ester (cellulose nitrate) as deposited from the solution in arnyl acetate. This purer anilin is .also suitable lor many or perhaps most qualities ci commercial celluloid ilms, butv the ap plicant has niet with qualities so resistant to the action of pure anihn as a solvent, that en'- deavors to stain the material with the anilin the `surface gofuiions given above weee futile. ln suoli 21.

one procedure is lo iisl slightly sollen the surface of the Celluloid with melliyl eleoliol. emyl ecelele, melone oi' like and ilieii 'lo apply the solution of dye in emilie.. All 'izei'iialii/ely 'die above .menlioiied solvents may be mixed Willi elle eeilin solulioii of the dye.

ln ease of e quality oi Celluloid which is exlremely resisleiil lo solvenls, iiilobenzeile may be used in e similar wey lo increase ille solvency of ille aiiilin oi" like. lm en exlieme cese ille staining dye may be dissolved iii elle` pure niliobenzeiie, but iii ell oi'dineiy ceses elle solvent oi' sofleiiimgg; poeh eis o' suoli e solm'ion would be excessive..

le elle use of nirtiobenzene espeoielly-by il sell llieie may be some cere iequiied in selectie@ e suiable color bui elle iiiiueiiloi' found Malachite @reen lo readily dissolve in a sample ol nilrobeiizene Wliieli lie lied pulcilied lo ille elmoel. llliis solution liepl; well for e few Weeks sind inslanlly seemed die l'iei'des eelluloid oil elle applieants selection.

mail lo seeking elle plebe iii weeli sull'ueic eem e eboul Il miiiules: one Weight uil-il el sulle io eoid 'lo from il@ lo lUO WeiglilnA ooloi applied ie eey ol eine beleg convenient.. The @lele dried. 'lfliis freemenl leeds lo iemove eey i. miduie wliioli may kmelee@ ed llie eolloid iesisl. appli/oprime lo ste-ie eed y be 'l of coi/m on 0023056? @weee .A ose @stew-To iiileilsiji' ille eofloid weee eli equeoiis solu'tioii ol en emilie dye should be used and tbe plebe should be lliorouglily dey ie @deia lliel; elle film el esleiJ meybeoeme lieid and compnet so es noi 'lo readily lelee solo@ leem en equeoiis solution. 'llaet elio pyioxyliii oi eslee should be el? elle lougli lifind Tellier there oi soll liind is sulioieelly im dieeeed ebove. le iiileeiisilyieg libe seele oli elle eellelofe essieu? surface, eeije sliould also be leken ibex?, elle plebe is eomplelely diy.

The piffocese ol? inleesieelioil is merely eil-- opeifeiloe dezeiled Hedel. libe lieede. .illy using e. siiilzeble dye, time les elle@ intensief/l may be modified elle iiileiisilloeliei'i.

The iiielsiuolioiis so lei eeive lo peo eee eoj poele@ color eeieeii awo Colois euoli sbowe by lligs l El, *elle 'lliiid Colm1 required beiiig'edded @allee- W imdegpeiideiil blue Teeling gwliieli ielly baltes elle fewo ooloi1 seieee 'ifely blue eoloi:J4 "melee in elle bollevu lsel'eeii is pressed, colei' eide are produced im llie film of Cellulose ester end llial the ied color is embodied in elle colloid :i1-reas. ll now a solution of enilin blue in emilie oi ils technical equivalent 'as herein indicated is i'uled or spi-'eyed or olliei- Wise applied, and aller blocing oil the plaie is li'eelsed in elle above mentioned souiinp; *belli llie'blue coloi` D will lelie only on the green erede C Wliele il. will be especially iequii'ed and will not lelie on the colloifl surface B charged willi red. lliernalively il elle colloid linee aie green, en equeous sollilion of blue dye will; or Without elle eddilion ol a. Weier soluble' eolloid may be sprayed or iuled oi* otherwise applied es e `soellelriiig over the Whole sueoe, and on iinsiiig obl with Wider, llie blue will leeve ils imprese moet notably oi' entirely on the green oolloid lilies. llie 'limes oi colors involved iii lliis kind oi .disciimineiive irreal:- lneiil may be varied eoooidiiig lo 1die requii'emenls of elle eoloim selieme.

llflien the blue is lo cross elle green oi'l perlly cover elle green am originel green of e yellowei time is indicated alien when lie green is lo fome peel; olZ e lere solo? sysli'e y. on elle olliei bend when elle gieeiiisli colei of allie two coloi? syslsem is e gieeiiisli blue (elleezilively e bluish greeel. elle lliiid ille above modes (diseiimmelgive oi geiieeel) may be yellow'.T iiieleed ol blue spec-filled le this eese elle yellow eve?? geeeiiisli-blue gives green by ebslieelioe oiv obslgeiiolioirl7 leaving; elle uneeveied' portions ofi greenish blue lo form emolsllei element of combination.

Mlle) flammable/e bel/weee. eempoele' especially expedida/e Coulee *edlen idexible surfaces or films ere ieqeieed foi ex posuie iii elle camere is le sleip elle comu posile ooloi' screen es piepeiedoe e.. L@less supplire end lo mouiibllie stripped eolieposile color isei'eeii eslei' side upweed, on ordiiiei'y eelluloid, lliis giving iiieil; oi" een eolive side loi eoeliiig 'Willi elle semsilive emulsion. FolB ellis purpose lille :veeeiviiigz suileoe of Celluloid should be mede slightly edbesi've es by e llziii eoelilig ol emyl eoelzde eollodion amd dee stripped oomposile coloi doifmweid, iiilo close comme eed e'dliesioe. le ellis operelioia lille leesl pireolieeble qiieeliey el edliesive should be used., `so ee lo minimize eey ieteidillusien or overlep ol eoloi. Heel; may be employed Willi piessmee, oe ellernolively lieel; end oloyed Willioue any adhesive. lliisleed our applying edliesive es suoli eelliiloid oi" eurleee may be moisleziefl. oio filmed 4 mieli oi cellulose eslei7 veiiiisli pepeed. mi exemple, emyl eeelel'e es e solir'eiie forees'iiie meg? be lll@ dll

hereinbefore specified, may now be applied:

thorough drying being efi'ected between the applications. Thus is built up any required thicknessof 4inert protective material between the composite color screen and the emulsion, or the composite 'color screen and any chemical used in after-treatment. The reason for using successive thin coatings is to prevent such softening of the whole mass as may lead to subversive interdifi'usion of the colors, and if desirable a' thin stratum of india rubber or resinous material may be used between any two coatings. The operation of transfer makes it practicable to thicken the back or front of the original film of cellulose ester or like, but where no transfer is made the india rubber substratum may conveniently cover the whole surface of the glass plate instead of being confined to the edges.

Although anilln is mentioned as a desirable solvent for such colors as is used to stain the cellulose ester, other solvents may be used, the whole range of what may be vaguely rtermed alcoholic etherial or aromatic solvents being more or less available, and the solvent must be selected in reference to the coloring body used. Preference is however given to basic solvents which are physically and chemically comparable to anilin: removal in an acid bath being easy, and in this connection may be mentioned the li uid toluidins (ortho-toluidin and metato uidin), whether alone or with anilin.

It should be understood that the composite color-screen produced as herein described by interdependent coloring and staining in stages may be formed on ordinary thin celluloid or on similar sheets of cellulose ester without camphor either after manufacture or while the celluloid is with or'on the mold'- ing plate or molding wheel, and emulsion may be laid on either side of the stripped sheet as may be expedient.

It should be understood that in its essence. the new technical effect realized by the present invention, namely a. clear and definite distinction between the colors of the composite color screen by|the hereinY described improvements as to interdependent coloring on a base oit'` cellulose ester or like, allows extremely fine composite color screens to be made without subversive overlap of the coloring; but the present invention also allows ot usual or even specially coarse screens for large subjects to be made ot a higher quality and luminosity than has hitherto been possible. The present invention therefore is `inlfierently applicable to the production of unusually large subjects orl im roved character.

Fluid bases having-a more decided alkalinity than anilin (or the above mentioned homologous bodies) or a greater miscibility with water, appear to be generally undesirable as solvents, or at any rate less desirable than anilin or like. As regards the matter of miscibility with water thereason is explained above, and as regards a higher degrec of alkalinity the disadvantage may atfect certain colors, more notably the methyl red which 'is mentioned above. The applicant found that pyridin, whether in the form sold as pure o1' that sold as commercial, very instantaneously destroys the red color of methyl red dissolved in anilin, and similarly a crude chinolin obtained by distilling cinchonin with potash destroys the red color of. methyl red which has already been dissolved in anil-in. As a comment it may be remarked that methyl red in a solution which is mainly aqueousis known to be highly sensitive to alkalis and alkaloids, hence its use as an indicator; anilin in its purer form as specified., however, was found not to dim the red color of the methyl red.

The applicant v avoidance of fluid bases like pyridin or chinolin (including lepidin and homologous bases) which tend to unite with water and which are notably more alkalin than anilin. In ruling lines of two or more colors in sequence on a surface, so that the lines fit together an essential condition is an exact outline of the lines without irregularity; otherwise the fit of line to line will be defective.` In relation to the mode of inter'- dependent staining herein described there is no necessit to rule the lines with straight or regular e ges and indeed a little irregularity may be' an advantage as breaking down or minimizing the regular lined effeet. Therefore the applicant finds it occasionally 'desirable to so vibrate lor irregularly move the ruling pen or deiiice as to give a rough or dotted aspect to the individual lines. There are4 well known mechanical means for doing this.

ln all heliochromic processes it may be expedient to introduce a neutral key element to conduce to critical. sharpness and also intensity, @ne way in which a neutral key canbe associated with results by the present process is to superimpose a weak monochrome taken actually from the same standpoint: any suitable or known optical device being used tor this purpose. Another mode suited for kinematograph projection is to alternatively produce, heliochromes, by the herein described process, and monochromes on the same tilin lens oit higher or deeper defining power being preferably used tor the monochrome alter'- nations. lin the iinal or exhibition the heliochronies and weak monochromes would be cast on the screen in alternation.

ai preliminary ruling 'or scattering in stain may be produced on the ester or celluloid base by tie following method this pre suggests as desirable the Ehh liminary staining corresponding in function with a third scattering or ruling on the two color system, so this preliminary ruling or scattering in stain will ordinarily be bl le, bluish, or in special cases yellow green.

n colloid ink or resist of the kind herein described, but of any convenient 'color or uncolored, a ruled or scattered resist islaid. This being dried but not insolubilized, the interspaces are stained with a solution of a dye in a solvent which softens the Celluloid, the conditions for selecting this being as hereinabove defined. The colloid ink (or dummy ink) is now washed off with water #and the surface of Celluloid or similar material is treated for two color effect as already described.

What ll claim is:

1. Process of forming a discriminative composite, color-screen suited to control a photographic monochrome, which process comprises laying colloid lines or areas with a fluid aqueous colored colloid on a` base which is non-absorbent for aqueous prepara'tions but is generally adsorbent and absorbent for alcoholic and aromatic preparations, then after drying staining the base by a solution of a dye in a duid which the base adsorbs; the color of the stain being broadly or generally antichromatic to the color in the aqueous colloid.

2. Process 'for the manufacture of polychrome screens for color photography which process comprises the following operations to wit, laying colloid areas with a duid aqueous colored colloid on a base of the nature described, and then after drying staining the uncovered parts of the base with a solution of a color broadly antichromatic to the color in the aqueous colloid and dissolved in a Huid of the nature described which the base can adsorb, but with the said base so thin that the second color cannot lpenetrate or diffuse laterally under the colloid lines to such degrees as to injl'ure the color combination by overlap of co or.

3. Process for the'manufacture of poly-i chrome screens for color photography which process comprises the following operations to wit, laying colloid areas with a Huid aqueous colored colloid on a base of the nature described, and then after drying staining the uncovered parts of the base with a solution. of a color broadly antichromatic to the color in the aqueous colloid and dissolved in a fluid of the. nature described which the base can adsorb, but with the application of the second color in short stages alternated with clearings off, so as to keep the stain well to the surface andminimize any lateral difusion under the colloid lines.

4. Process for the manufacture of poly- Chrome screens for color photography which chrome screens for color photography which process comprises the following operations to wit, laying colloid areas with a fluid aqueous colored colloid on a base of the nature described and then after drying staining the uncovered parts of the base with a solution of a color broadly antichromatic to the color in the aqueous colloid and dissolved in a fluid of the nature described which vthe base can adsorb, but with immersion of the doubly colored base in a fluid of the nature described calculated to clearer remove traces of the second color from the colloid lines.

5. Process for the manufacture of polychrome screens for color photography which process comprises the following operations to wit, laying colloid areas with a fluid aqueous colored colloid on a base of the nature described, and then after drying staining the uncovered parts of the base with a solution of a color broadly antichromatic to the color in the aqueous colloid and dissolved in a fluid of the nature described which the base can adsorb, but with a special or high degree of desiccation of the colloid lines or areas, in order to render such lines or areas inactive to the second application of color.

6. Process for the manufacture of polyprocess comprises vthe following operations tc wit, laying colloid areas with a fluid aqueous colored colloid on a base of the nature described, and then after drying staining the uncovered parts of the base with a solution of a colorbroadly antichromatic to the color in the aqueous colloid and dissolved in a fluid of the nature described .which the base can adsorb, but with the water soluble colloid preparation suited for insolubilization by the vapor of formaldehyde; the water soluble lines being made insoluble by the vapor of formaldehyde.

7. Process for the manufacture of polychrome screens for color photography which process comprises the following o erations z-to wit, laying colloid areas wlth a fluid aqueous colored colloid on a base of celluloid ester, and then after drying staining the uncovered parts of the base with a solution of a color broadly antichromatic to the color in the aqueous colloid and dissolved in a fluid of the nature described which the base can adsorb, but with the after mounting of the film of ester bearing the composite color-screen on a. firmer support.

8. Process for the manufacture of polychrome screens for color photography which process comprises the following operationsz-to Wit, laying colloid areas with a fluid aqueous colored colloid on abase of the nature described, and then 'after drying staining the uncovered parts of Athe base with a solution of a color broadly antichromatic to the color in the aqueous colloid 130 and dissolved in a fluid of the nature described which the base can adsorb, but with an after-intensification of the color in the colloid areas by immersion in an aqueous solution of dye.

9. Process for the manufacture of polychrome screens for color photography which process comprises the following operatibns:,to' wit, laying collod areas' with a fluid aqueous colored colloid on a base of the nature described and then after drying staining the uncovered parts of the base .with a solution of a color broadly anti-4 chromatic to the color in the aqueous colloid and dissolved in a fluid of the nature described Which the base can adsorb, butwith an after. intensification of the color on the base by the application of a dye dissolved in a fluid of the nature described.

10. .Process for the manufacture of polychrome screens for color photography which process comprises the operations set forth in claim l, and, on a two-color system of color areas thus produced, overplacing a system of sup lementary color-areas.

11. olor screen on a base of the nature described which carries colored areas in colloid, and antichromatic areas in stain on the base, said colloid areas having intimate Contact with the base, smooth exterior, and closely sealed edge.

12. Processfor th manufacture of polychrome screens for color photography,v

which process comprises a preliminary partial stainng of a base of the nature described under the control of colloid areas of resist, Washing off such areas of resist, then on said base laying colloid areas with a iuid aqueous colored colloid, and then after drying staining the base by a solution of a dye in a fluid which' the base adsorbs; the color of the stain being broadly or generally antichromatic to the color in the aqueous colloid.

In testimony whereof I aix my signature JOSEPH THOMAS SMITH. 

